Thread: Angles at a point

Hi all, im a new member and a high shcool Algerbra student. Im having quite a bit of trouble with this homework(which is being graded as a quiz ) To start, i dont under stand what some of the questions are asking me, for example the first one is(this is in the intergrated algerbra AMSCO text book pgs 294-295 if any of you happent to have it ) the first question is if line AB and line CD intersect at E, Angle AEC=2=x+10 and angle DEB=2x-30, find angle AEC I have no idea how to even set this up, my own notes dont even explain it. I would be very apreceative if anyone could help

Originally Posted by Thor

Hi all, im a new member and a high shcool Algerbra student. Im having quite a bit of trouble with this homework(which is being graded as a quiz ) To start, i dont under stand what some of the questions are asking me, for example the first one is(this is in the intergrated algerbra AMSCO text book pgs 294-295 if any of you happent to have it ) the first question is if line AB and line CD intersect at E, Angle AEC=2=x+10 and angle DEB=2x-30, find angle AEC I have no idea how to even set this up, my own notes dont even explain it. I would be very apreceative if anyone could help

did you draw a diagram?

recall that angles at a point sum to 360 degrees. so,

AED + DEB + BEC + AEC = 360

as this will be graded as a quiz, that's all the help you'll get. you finish up the rest

Im sorry, but i didnt quite understand what you ment, do you mean i have to set it up like a let statment type problem? As for the diagram, i drew one up in MS pain

Originally Posted by Thor

Im sorry, but i didnt quite understand what you ment, do you mean i have to set it up like a let statment type problem? As for the diagram, i drew one up in MS pain

Hmm, I have no idea how you got that diagram. the line CD doesn't even intersect AB and you have three extra points G, H and F. clearly it can't be right.

the correct diagram is below.

OH! *facepalm* I was using a diagram the text book page had given me that looks similart to what i thought it would look like....Sorry, but i think i got it figured out.

I think its x+10+2x-30=360
3x-20=360
3x=380
x=126.6....

But the check for it comes out to be 359.8, but then again i suck at math....so this is wrong correct?

Originally Posted by Thor

OH! *facepalm* I was using a diagram the text book page had given me that looks similart to what i thought it would look like....Sorry, but i think i got it figured out.

I think its x+10+2x-30=360
3x-20=360
3x=380
x=126.6....

But the check for it comes out to be 359.8, but then again i suck at math....so this is wrong correct?

i wouldn't use decimals. leave your answers in terms of fractions and you will get the exact answer.

anyway, note that my equation has four angles in it. yours has two.

Final Hint: see number 10 here

that will give you the right equation to solve for x. note that "x" is NOT what you are looking for. you use it to find your answer.

OH!!!!! Now i think i get it... Much thanks man!

EDIT: I think i did somthing wrong though....